Blower.



C. V. KERR.

BLOWER.

APPUCAIION FILED AUG. 15. 19:3.

Patented Apr. 20, 1915.

as a number of stationary blades or vanes.

MRJLES VOLNEY KERR, 01E WELLSVILLJE, NEW YO 1:: 1..

*Btowna.

meat la.

Application filed August 15, 191 s. semi no. 785,009.

To all whom it may concern Be it known that 1, CHARLES V. KERR, acitizen of the United States, residing at Wellsville, New York, haveinvented a certain new and useful Blower, of which the following is aspecification.

()ne object of my invention is to increase the eliiciency of blowersemployed for forced draft, or ether purposes, by providing improveddififiisionl -ineans which prevent losses by eddy-currents, e Moreparticularly, I accomplish-t result by employing, at the dischargesidebf the fan, an annular discharge nozzle, and in this nozzle Iprovide These blades are preferably curved so that they receive air fromthe fan traveling in its normal direction and discharge this air 5radially. In effect, these blades divide the annular discharge ordiffusion nozzle into a plurality of nozzles, in place of the usualvolute casing, each of which is larger at the discharge end than at theinner end. Air passing into the small ends of the nozzles is thusreduced in velocity with increase of pressure so that the kineticenergy. imparted by the fan is most efficiently converted into potentialenergy. Air is discharged from the circular, vaned difl'user into aninclosed space such as the stokehole of a vessel for example, and thecombination specified is especially adapted to maintain suitablepressure in such an. inclosure in an efiicient manner and without theprovision of a volute casing which is frequently employed incompressors.

Another principal object of the invention is to reduce the noise ofblower-fans and the like by making the number fan and the number ofblades in the difl'user prime to each other. This prevents the wholenumber of blades in the rotor and.

- Specification of Letters Patent.

of blades in the juice to eah Patented Apr. 2 0, TQM.

plan and partly in section of half of the apparatus, and Fig. 2 is avertical section.

Reference character ldesignates a suction passage leading through thedeck 2 of a vessel, or the like; This suction passage terminates in whatmay-be identified as a suc.

The impeller shaft 4 suption-throat 3. ports impeller 5 within thethroat. At the discharge side of the impeller is deflector 6, preferablyof conoidal shape. The inner end of suction-throat 3 is curved andflanged outward, and an annular diffuser surrounding thedefiect'or isformed by plates 7 and 8 secured to the suction-throat and outer edge ofthe deflector, respectively. \Vithin this diffusion ring or nozzle are aplurality of vertical diffusion blades or vanes 9, and these arepreferably curved, as shown in Fig. 1. The diffusion ring thusconstitutes essentially a multiple volute discharge casing. Air isdischarged by the fan through the space between the suction-throat andthe deflector, and strikes the inner ends of the difi'usion vanes innearly tangential lines, as indicated by the arrows, Fig. 1, and thevanes direct this air outward in radial lines, as shown. Thecross-sectional area of each subordinate nozzle increases from the inletto the outlet sides, and thus each component part of the diffusion ringforms'part of a volute casing. To reduce noise in the way abovesuggested, the number of blades in the fan may, for example, bethirty-one, and the number of blades in the diffuser may be thirty-two.These numbers are prime to each other, and,

* therefore, produce the desired result in re Other numbers of bladesother may be chosen, but it will probably usually be desirable to makethe number of blades closely approach each other, although this is notan essential limitation.

ducing noise.

M designates a suitable motor, such as a steam turbine mounted on theimpeller shaft and suitably suspended. Any suitable hlghspeed motordesigned to cooperate with the impeller may, of courseabe employed.

The invention is ,designed for advantageous use of an impeller of thekind described in my previous pending applications, .Serial Numbers648,584 and 665,785,

although it is notlimited to the use ofthat form'of impeller.

operation.

I claim:

1. In a blower or the like, a bladed im- Ipeller and .a difl'user havingstationary lades, and diffuser being prime to each other.

2. In a blower or the like, the combination of a rotary bladed impellerdesigned to move air axially, a deflector at the discharge side of theimpeller, an annular diffusion ring at the periphery of the deflector,said ring being in a plane parallel to the rotative plane of theimpeller, and diffusion I the fiumber of .blades in the impeller tion ofa suction inlet, an impeller for moving air axially rotatably supportedwithin said inlet, a stationary deflector at the discharge side of theimpeller arranged to receive air moving axially and to deliver itspirally outward, an annular series of diffusion vanes to receive airfrom the deflector and deliver it radially outward, and an inclosure forcontaining air under pressure wherein said difi'usion vanes are located.

5. In a blower or the like, the combination of a suction inlet, animpeller rotatably mounted therein and constructed and arranged to moveair spirally away from said inlet, an annular series of diffusion vanesarranged concentric with said impeller to receive air therefrom anddeliver it radially outward, and an inclosed space wherein said seriesof diffusion vanes is mounted for containing air under pressure.

CHARLES VOLNEY KERR.

Witnesses:

CHAS. O. LIVERMORE, VOLINEY A. KERR.

